Current work includes studies on plasma membrane biogenesis, including the sites of synthesis and assembly of phospholipids and of enzymatic proteins. The approach utilizes combined biochemical, cytochemical and electron microscopic techniques and the major studies involve secreting cells of the ducklings' salt gland stressed by salt ingestion. Other systems evincing biogenesis of membranes shall also be studied. A second aspect involves enzymatic composition of plasma membrane and enzymes involved in phospholipid synthesis. Although these studies are related to those in biogenesis, the main emphasis concerns Na ion K ion ATPase (development of an immunocytochemical method and utilizing ouabain derivatives to localize the activity), phosphatidic acid phosphatase and CDP amine and other diglyceride transferases, the last step in the synthesis of specific glycerophospholipids. Some of these methods shall be applied to studies involving type II pneunocytes and the biogenesis of pulmonary surfactant. BIBLIOGRAPHIC REFERENCES: Heckman, C.A., Friedman, S.J., Skehan, P.J. and Barrnett, R.J. Localization and partial characterization of acyltransferases present during rapid membrane formation in Drosophila melanogaster embryo. Develop. Biol., In press. White, D.L., Andrews, S.B., Faller, J.W. and Barrnett, R.J. 1976. The chemical nature of osmium tetroxide fixation and staining of membranes by X-ray photoelectron spectroscopy. Biochim. Biophys. Acta., Biomembranes. In press.